The correct answer is: A. Beas River.
The Bhabour Sahib Phase-II Project is a hydroelectric project located on the Beas River in the Una district of Himachal Pradesh, India. The project was commissioned in 2015 and has a installed capacity of 100 MW. The project consists of a dam, a power house, and a canal system. The dam is located on the Beas River, about 10 km upstream of the town of Una. The power house is located at the foot of the dam and consists of four turbines. The canal system is used to divert water from the Beas River to irrigate agricultural land in the Una district.
The other options are incorrect because they are not sources of water supply for the Bhabour Sahib Phase-II Project. The Swan River is a tributary of the Beas River and is located in the Kangra district of Himachal Pradesh. The Nangal Dam is a hydroelectric dam located on the Sutlej River in the Rupnagar district of Punjab. The Pong Dam is a hydroelectric dam located on the Beas River in the Kangra district of Himachal Pradesh.